The acidulation of meat products, particularly meat emulsions, is well known. Meat emulsions, for instance sausage emulsions, are mixtures of lean meat or meat protein and water forming a matrix in which fat particles, salt, sugar and curing agents are dispersed. It is well known that the emulsifying action generally decreases with increasing acidity of the emulsion. Specifically, the water-binding capacity and the emulsifying qualities of the meat protein are affected by the emulsion pH. To obtain a stable emulsion, it is necessary to avoid the presence of too much acid during the preparation and processing of the emulsion. Generally the emulsions are stable when the critical pH is about 6 or higher.
However, it is desirable to achieve a pH lower than about 6 in the final product to enhance flavor, texture and keepability. It has been observed that a pH decrease after the emulsion is formed does not generally alter the initial quality of the emulsion, which by that time is comparatively stable. Reference can be had in this regard to U.S. Pat. No. 2,992,116, obtained by Louis Sair; and British Pat. No. 1,138,765 (Unilever Ltd.).
Both of these patents propose the use of an acidulant which can be incorporated into the meat emulsion prior to processing the emulsion, but which has a delayed reaction, so that acidulation takes place subsequent to emulsification. In the U.S. Pat. No. 2,992,116 patent, the agent is glucono delta lactone, which slowly hydrolizes to form gluconic acid. In the British Pat. No. 1,138,765, the agent is a lactide such as DL-lactide (meso-form).
Neither acidulant has met with substantial commercial success. For instance, because of premature hydrolysis and unreliability regarding the rate of reaction and flavor, glucono delta lactone (GDL) has been used only very cautiously in the sausage industry, and some companies have discontinued use of the same altogether. DL-Lactide is not permitted by law as an ingredient in the United States, and its commercial availability is limited.
In prior U.S. Pat. No. 3,359,120, coated fumaric acid is proposed as an acidulant for meat emulsions to enhance color and color stability. The coating, in this patent, can be either a wax, monoglyceride, or vegetable oil. Processing temperatures in the processing of the meat product, for instance smoke house temperatures, cause the coatings to melt, releasing the fumaric acid and resulting in color development. One problem with this procedure is that not all meats are processed using high temperatures, for instance summer sausages. Also, as suggested in the Delaney U.S. Pat. No. 3,560,222, some difficulty may be experienced in obtaining a uniform thin coating completely or substantially completely covering the acid crystals. In the Delaney patent, this problem is said to be overcome by providing an inner water soluble coat, partly enveloping and encasing the acid crystals, followed by an outer, inert, water insoluble, heat-rupturable coating completely enveloping the particulate acidulant. The problem with the procedure of this patent is that one still needs heat to rupture the outer coating, and again, not all meats are processed using heat. The inner water-soluble coat, referred to as a vehicle, in the patent, may be a gum such as gum arabic and cebil gum, an inert salt exemplified by sodium caseinate, gelatin, sugar, confectioner's glaze, and the like. Another problem with fumaric acid is its undesirable characteristic flavor.
Concerning the above patents, a distinction has to be made between acidification for fixing color and acidification for texture and meat preservation. Normally, the former requires less than about 0.1% free acid, and the latter about 0.5-2% free acid.
Related to the above two patents is recently issued U.S. Pat. No. 4,262,027 (Tonner et al.) on the use of a water soluble hydrocolloid (e.g. gum) along with a fat encapsulated acidogen during the acidification process. The product also would not be useful in an acidulation process where heat is not used.
Prior U.S. Pat. No. 3,131,068 (Grelf et al.) describes coating a solid acidulant with water soluble hydroxypropyl methylcellulose. This material, which is not highly water soluble, requires the use of a solvent, such as chloroform or ethylene dichloride, during application of the coating. Disadvantages are the cost of use of a solvent and its possible toxicity as well as its insolubility.
It is known to use starch as a matrix or carrier for food additives. Generally, such food additives are liquid materials such as oleo resins, essential oils, and flavorants. Examples are given in U.S. Pat. No. 2,170,954 (to Stange), disclosing the use of a gelatinized starch; in U.S. Pat. No. 2,876,160 (to Schoch et al.), which disloses the use of dextrins having high solubility in cold water (e.g. 80% solubility or above), the dextrin forming a matrix for such materials as vitamin A; U.S. Pat. No. 3,091,567 (to Wurzburg et al.), disclosing the use of an ungelatinized starch acid ester for encapsulating water-insoluble flavors, perfumes, and other substances; U.S. Pat. No. 3,159,585 (to Evans et al.), on the use of the dextrins derived from oxidized starches (containing a controlled amount of carboxyl groups) for encapsulation of volatile materials such as flavoring oils and perfumes; U.S. Pat. No. 3,499,962 (to Wurzburg et al.), on the use of an amylose product for encapsulating water insoluble materials; U.S. Pat. No. 3,819,838 (to Smith et al.), on the use of "modified starch" for encapsulating essential oils, oleo resins and other flavoring essences, and U.S. Pat. No. 3,821,436 (to Fry), on the use of a starch hydrolysate having a D.E. less than about 40, as a carrier "for flavoring agent". In all of the above cases, the products are generally made by forming a mixture of the carrier and active ingredients and subjecting the same to spray drying or other similar procedure, followed by some form of maceration to obtain fine particles. In none of the procedures is it clear that a product is obtained of uniformly small particle size in which a core particle is enveloped by a thin, protective layer.